The present invention generally relates to an air cleaning machine to be used in houses, offices and so on.
The conventional air cleaning machine of this type has adsorbent such as activated charcoal or the like filled in the filter portion through which the air is passed by a fan, so that the deodorizing operation is effected (some air cleaning machines are provided with a high-voltage means for catching dust with static electricity or the like, and a filter portion). The air cleaning means detects the gas concentration of the gas to be removed inside the room or the like to automatically start the machine to clean the air.
However, the conventional gas sensor cannot produce an output signal unless the gas to be reacted to reaches the gas sensor through the movement of the air or diffusion in the air. Accordingly, the conventional gas sensor had disadvantages in that 5 minutes or 20 minutes may be taken to start the operation of the appliance after the gas to be removed is generated (the start depending upon the indoor condition, the wind direction, the gas concentration or the like), or 40 to 50 minutes may be taken before the operation. It is an extremely important problem when a faster operation is desired at the early stage.